This invention relates generally to an insulating liner system for railroad and highway tunnels to eliminate ice buildup on the tunnel crown, walls and roadbed caused by freezing of water leakage from the tunnel face. The invention disclosed herein is a modification of my U.S. Pat. No. 4,940,360 which was designed for high flexural strength and section modulus to withstand minor rockfall on exposed rock face tunnels and to accommodate filling of the annular space between the rock face and the liner system with a lightweight concrete material to preclude future rockfall.
The present invention is designed for application on wet concrete-faced tunnels where high-strength is not a requirement. By substituting an elastomeric coating on the back face of the insulating core for the sheet metal back face of the original panel, the panels can be fabricated flat and formed to the tunnel configuration during installation thus substantially reducing the cost of fabrication and installation.